<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let num = 10
        const age = 20
        console.log(num)
        console.log(age)

        const arr = []
        const student = {
            name:"张三",
            age:18
        }
        arr.push(1)
        arr.push(2)
        arr.push(3)
        student.addr = "贵州"

        console.log(arr)
        console.log(student)
    </script>
</body>
</html>